[Isotopic ventriculography in healthy young volunteers. Their response to different types of stress]

Due to the increasing use of pharmacologic stress tests and the lack of comparative studies on ventricular function, this study was designed to establish the average limits in ventricular function with different kinds of stress, and to compare the response among them.

A randomized, open, controlled phase II clinical trial in 4 parallel groups was designed. Forty healthy male volunteers between 18 and 25 years were randomized into 4 groups of 10 individuals each: physical exercise (group 1), dobutamine (group 2), adenosine triphosphate (ATP) (group 3) and dipyridamole (group 4). Each volunteer underwent equilibrium radionuclide angiography, at rest and during stress.

The global and regional ejection fraction increased significantly with the 4 kinds of stress. The maximal increase was reached with dobutamine and the minimal with dipyridamole. Physical exercise induced an increase in global ejection of 13 +/- 5%; dobutamine 16 +/- 6%; ATP 9 +/- 3% and dipyridamole 4 +/- 3%.

The global and regional ejection fraction increases significantly more with dobutamine than with the other stress tests. Dipyridamole elicits the minimal increase.